Polyvinyl acetate latex white paint base compositions containing a dispersant for paint tint colorants

ABSTRACT

IMPROVED COLOR DEVELOPMENT AND A WIDE RANGE OF PAINT TINT COLORANT COMPATIBILITY IS ACHIEVED IN POLYVINYL ACETATE LATEX WHITE PAINT BASE COMPSOITIONS CONTAINING A WHITE PIGMENT AND A DISPERSING AGENT, BY THE ADDITION THERETO OF A SMALL AMOUTH EFFECTIVE AS A COLORANT DISPERSANT, OF AN AMMONIUM SALT OF A PARTIAL ESTER OF A STYRENE-MALEIC ANHYDRIDE POLYMERESTERFIED TO ABOUT 75 10 100% HALF ESTER WITH AN ALKYLPHENYL ETHER ALCOHOL OF THE FORMULA   R-C6H4-(OCH2CH2)X-OH   WHERE R IS ALKYL OF 8 TO 9 CARBON ATOMS AND X IS 1 TO 30, SUCH AS P-TERITARY OCTYLPHENYL POLYETHOXY ALOCHOL OF 9 TO 10 ETHOXY GROUPS THE STYRENE-MALEIC ANHYDRIDE POLYMER PRIOR TO ESTERIFICATION CONTAINING A MOLAR RATIO OF POLYMERIZED STYRENE TO POLYMERIZED MALEIC ANHYDRIDE OF ABOUT 1:1 TO 4:1, AND PREFERABLY OF ABOUT 1:1, AND HAVING AN AVERAGE MOLECULAR WEIGHT OF ABOUT 600 TO 5000, POREFERABLY ABOUT 1500 TO 2000. OPTIMUM COLOR DEVELOPMENT IS OBTAINED WHEN THE DISPERSING AGENT COMPRISES A SMALL EFFECTIVE AMOUNT OF AN AMMONIUM SALT OF A PARTIAL ESTER OF THE AFORESAID STYRENE-MALEIC ANHYDRIDE POLYMER ESTERFIED TO ABOUT 75 TO 100% HALF ESTER WITH AN ALKYL ETHER OF ETHYLENE GLYCOL OR OF DIETHYLENE GLYCOL, SUCH AS THE MONOBUTYL ETHER OF ETHYLENE GLYCOL. THIS DISPERSING AGENT AND THE COLORANT DISPERSANT CAN BE MIXED TOGERTHER TO FORM AN EFFECTIVE COLORANT TINT PAINT DISPERSANT COMPOSITION FOR ADDITION TO POLYVINYL ACETATE LATEX WHITE PAINT BASE COMPOSITIONS. THE PAINT TINT COLORANT IS SUBSEQUIENTLY ADDED TO THE POLYVINYL ACETATE LATEX WHITE PAINT BASE COMPOSITION CONTAINING THE COLORAND DISPERSANT RESULTING IN EXCELLENT COMPATIBILITY AND COLOR DEVELOPMENT.

United States Patent 3,639,325 POLYVINYL ACETATE LATEX WHITE PAINT BASE COMPOSITIONS CONTAINING A DIS- PERSANT FOR PAINT TINT COLORANTS Donald L. Marion, Homewood, Dennis G. Anderson,

Chicago, and Robert C. Strand, Homewood, Ill., assignors to Atlantic Richfield Company No Drawing. Filed Mar. 15, 1968, Ser. No. 713,291 Int. Cl. C08f 3/70, 29/48; C09d 3/76 US. Cl. 26029.6 4 Claims ABSTRACT OF THE DISCLOSURE Improved color development and a wide range of paint tint colorant compatibility is achieved in polyvinyl acetate latex white paint base compositions containing a white pigment and a dispersing agent, by the addition thereto of a small amount effective as a colorant dispersant, of an ammonium salt of a partial ester of a styrene-maleic anhydride polymer esterified to about 75 to 100% half ester with an alkylphenyl ether alcohol of the formula where R is alkyl of 8 to 9 carbon atoms and x is 1 to 30, such as p-tertiary octylphenyl polyethoxy alcohol of 9 to 10 ethoxy groups, the styrene-maleic anhydride polymer prior to esterification containing a molar ratio of polymerized styrene to polymerized maleic anhydride of about 1:1 to 4:1, and preferably of about 1:1, and having an average molecular weight of about 600 to 5000, preferably about 1500 to 2000. Optimum color development is obtained when the dispersing agent comprises a small effective amount of an ammonium salt of a partial ester of the aforesaid styrene-maleic anhydride polymer esterified to about 75 to 100% half ester with an alkyl ether of ethylene glycol or of diethylene glycol, such as the monobutyl ether of ethylene glycol. This dispersing agent and the colorant dispersant can be mixed together to form an effective colorant tint paint dispersant composition for addition to polyvinyl acetate latex white paint base compositions. The paint tint colorant is subsequently added to the polyvinyl acetate latex white paint base composition containing the colorant dispersant resulting in excellent compatibility and color development.

This invention relates to polyvinyl acetate latex paint compositions. More particularly, this invention relates to polyvinyl acetate latex White paint base compositions containing colorant dispersions with improved compatibility and color development.

Within recent years the practice of tinting trade sales paints in the retail store at the time of purchase has become widespread. Either solvent-thinned (mineral spirits) or latex paints can be tinted to the desired color by using the same colorants. This is accomplished by machine-dispensing measured amounts of the universal colorants into a white paint base. Color development is achieved simply by mixing on a paint shaker.

There are a number of advantages obtained by employing a white paint base and coloring it with a universal colorant at the time of purchase in the retail store. Some of the more significant advantages which are realized with systems of this type are: (1,) paint manufacturers can attain higher production volume, since some in-factory tinting is eliminated; (2) inventory of various colors for both the manufacturer and the retailer is simplified; (3) an extensive selection of paint colors is available and (4) aesthetic appeal to the consumer is developed since Patented Feb. 1, 1972 the color selection is a more unique or personalized choice.

Optimum color development is dependent on specific components present in each paint formulation, such as pigment dispersants, emulsifiers, and protective colloids. Paint formulations of each manufacturer must be specifically tailored to accept or be compatible with these colorants. Often the vehicle system in these colorants is based upon linseed oil which has been chemically modified to achieve hydrophilic characteristics. Performance requirements are stringent. Some of these universal colorants are offered in different series of various colorants each. Many of these universal colorants seek to achieve package stability and compatibility when used in both solvent-based and latex paints. Thus the hydrophilic-hydrophobic balance of the resin system and pigment dispersants used in these color systems are important. Heretofore, various latex paint formulations have sought to achieve compatibility with these commercial universal colorants by including in the latex paint formulations substantial amounts of multicomponent dispersant systems. Development of a latex paint composition which has a full range of colorant compatibility would be a significant technical accomplishment.

It has been discovered in accordance with this invention that excellent paint tint colorant compatibility and development is obtained in polyvinyl acetate latex white paint base compositions containing a white pigment and a dispersing agent, by the addition of a small amount, effective as a colorant dispersant, of an ammonium salt of a partial ester of a styrene-maleic anhydride polymer esterified to about to half ester with an alkylphenyl ether alcohol of the formula where R is alkyl of 8 to 9 carbon atoms and x is 1 to 30, the styrene-maleic anhydride polymer prior to esterification containing a molar ratio of polymerized styrene to polymerized maleic anhydride of about 1:1 to 4:1, preferably of about 1:1, and having an average molecular weight of about 600 to 5000, preferably about 1500 to 2000.

It is preferred that x in the formula be at least 2, such as about 5 or 6 to 14 or 15. R is preferably octyl, such as tertiary-octyl. These alkylphenyl polyethoxy alcohols include octylphenyl polyethoxy alcohol containing 9 to 10 ethoxy groups which is a well known commercial product (Triton X-100). It is produced by the reaction of t-octyl henol with ethylene oxide and can be represented by the formula:

The alkylphenyl polyethoxy alcohols also can be named alkylphenoxy polyethoxyethanols represented by the formula:

ice

where R and x are as aforesaid. Thus octylphenyl polyethoxy alcohol also can be named octylphenoxy polyethoxyethauol represented by the formula:

Optimum color development is obtained when the dispersing agent comprises a small effective amount of an ammonium salt of a partial ester of a styrene-maleic anhydride polymer esterified to about 75 to 100% half ester with an alkyl ether of ethylene glycol or of diethylene glycol, where alkyl is 1 to 8 carbon atoms, such as the monobutyl ether of ethylene glycol, and the styrenemaleic anhydride polymer prior to esterification contains a molar ratio of polymerized styrene to polymerized maleic anhydride of about 1:1 to 1:4, preferably about 1:1, and has an average molecular weight of about 600 to 5000, preferably about 1500 to 2000.

A small effective amount of an ammonium salt of the alkylphenyl ethoxy alcohol partial ester of the styrenemaleic anhydride polymer can be added and incorporated by stirring into the polyvinyl acetate white paint base composition at the time the white paint base composition is formulated or afterwards prior to the addition of the paint tint colorant. The amount of the ammonium salt of the alkylphenyl ethoxy alcohol partial ester of the styrene-maleic anhydride polymer, based on 100% active basis, i.e., non-volatile resin, may vary from about 0.5% to 5% or more by weight of the pigment in the white paint base composition. Usually this ammonium salt of the alkylphenyl ethoxy alcohol partial ester, based on 100% active basis, i.e.' non-volatile resin, is about 0.5 to

3% and preferably about 1% to 2% by weight of the pigment. Only an amount of the ammonium salt of this alkylphenyl ethoxy alcohol partial ester need be used which is sufiicient to effectively disperse the paint tint colorant without flocculation, although more can be used if desired.

To obtain optimum results, it is desirable to incorporate a small amount of the ammonium salt of the alkyl ether glycol partial ester of the styrene-maleic anhydride polymer during the pigment dispersion process of the paint making operation. The amount of the ammonium salt of the alkyl ether glycol partial ester, based on this partial ester non-volatile resin, may vary from about 0.5% to 5% or more by weight of the pigment in the white paint base composition. Usually this ammonium salt of the alkyl ether glycol partial ester, based on 100% active base, i.e. non-volatile resin, is about 0.5 to 2%, and preferably about 1 to 1.5%, 'by weight of the pigment to obtain optimum results, although more can be used, if desired.

The ammonium salt of the alkylphenyl ethoxy alcohol partial ester and the ammonium salt of the alkyl ether glycol partial ester can be separately introduced, or mixed together and introduced during the pigment dispersion process. The ratio of the ammonium salt of the alkylphenyl ethoxy alcohol partial ester to the ammonium salt of the alkyl ether :glycol partial ester, on a 100% active basis, is usually about 0.5 :1 to 2:1 and preferably about 1.2:1 to 1:1. However, the ammonium salt of the alkylphenyl ethoxy alcohol partial ester can be introduced as an additive after the pigment is dispersed with the ammonium salt of the alkyl ether glycol partial ester.

Any paint tint colorant, such as the various commercial paint tint colorants, can be dispersed in polyvinyl acetate latex white paint base formulations containing the alkylphenyl ethoxy alcohol partial esters of styrene-maleic anhydride polymer in accordance with this invention. These paint tint colorants are usually used in amounts of about 1 to 16 oz. and preferably about 4 to 8 oz. per

gallon of polyvinyl acetate latex white paint base formulation.

Styrene and maleic anhydride can be polymerized t form low molecular weight polymers for use in this invention by conventional polymerization methods. Solution polymerization methods can be employed where the monomers are polymerized in a suitable solvent using as a polymerization catalyst a free-radical catalyst, such as a peroxide, preferably benzoyl peroxide, dicumyl peroxide or an alkyl peroxy dicarbonate, at a temperature of about 75 to 300 C. or more. Suitable solvents include the aromatic hydrocarbon solvents, such as cumene, p-cymene, xylene, toluene, etc. Other suitable solvents are the ketones, such as methylethyl ketone. A preferred manner of carrying out the polymerization is by what is known as incremental feed addition. By this method the monomers and catalyst are first dissolved in a portion of the solvent in which the polymerization is to be conducted and the resulting solution fed in increments into 4 a reactor containing solvent heated to reaction temperature, usually the reflux temperature of the mixture.

When an aromatic solvent is employed as the solvent for the polymerization, the formation of the polymer causes a heterogeneous system, the polymer layer-being the heavier layer and recoverable by merely decanting the upper aromatic solvent layer and drying. On the other hand, when a ketone is the solvent, the formed copolymer is usually soluble in the solvent media so that recovery of the product necessitates a solvent-stripping operation. It is preferred that the polymer contain a molar ratio of polymerized styrene to polymerized maleic anhydride of about 1:1 although ratios of up to about 4:1 can be obtained by adjusting the mole ratio of styrene to maleic anhydride in the polymerization reaction. These low molecular weight polymers have molecular weights of about 600 to 5000, preferably about 1500-2000.

The partial esters of these styrene maleic anhydride polymers esterified to about 75 to half-ester respectively with the alkylphenyl ethoxy alcohol and with the alkyl ether glycol can be prepared in any conventional manner. By 100% half-ester is meant that half of the total number of carboxyl groups in the styrene-maleic anhydride polymer are esterified leaving the remaining half of the carboxyl groups unesterified and available for forming ammonium salt groups. The'partial ester of styrene-maleic anhydride polymer with tertiary octylphenyl polyethoxy alcohol containing 9 to 10 ethoxy groups (Triton X-100) is prepared as follows:

EXAMPLE A 100 grams of a styrene-maleic anhydride polymer, having a 1:1 ratio of styrene to moleic anhydride and a molecular weight range of 1600-1800 with the average number of styrene-maleic anhydride repeating units being about 8-9, is charged to a reaction kettle with 262 grams of the tertiary-octylphenyl polyethoxy alcohol containing 9-10 ethoxy groups (Triton X-100). The reaction kettle is fitted with a stirrer, thermometer, nitrogen sparge tube and condenser. Heat is gradually applied for 1%2-2 hours to a reaction temperature of 340-350 IF. This reaction temperature is held for 2 /z-3 hours, at which time the reaction is terminated.

The percent of half ester, based on acid number of the product, is 94% half ester of the styrene-maleic anhydride polymer esterified with the tertiary-octylphenyl polyethoxy alcohol. (Triton X-100.) The physical characteristics of this styrene-maleic anhydride partial ester of octylphenyl polyethoxy alcohol are as follows:

For:mViscous liquid Viscosity (Gardner-Holdt at 25 C.)

87.5% NVR in xylene-M 62.5% NVR in xyleneB Color (Gardner)l3 Acid number-68.0

Specific viscosity at 30 C. (10 gms./ 100 ml. acetone)- SolubilityReadily soluble in aqueous ammonia solution and in xylene.

The ammonium salt of this partial ester is prepared as follows:

EXAMPLE B grams of the partial ester of Example A and 220 grams of 28% ammonium hydroxide with 430 grams of water are charged to a reaction :kettle fitted with stirrer, thermometer and condenser. These materials are heated to 110-130 F. and held at this temperature for approximately one hour. The pH of the water solution containing 14.5% of the soluble ammonium salt of the partial ester as non-volatile-solid is 8.5-9.5.

EXAMPLE C The 1:1 styrene-maleic anhydride polymer having a molecular weight of 1600-1800 is esterified to about 100% half ester with monobutyl ether of ethylene glycol Example I (Butyl Cellosolve) in accordance with the general esterification procedure set forth in Example A. A hydrolyzed solution of the ammonium salt of this partial ester is prepared as follows: 320 parts of the above partial ester of 1:1 styrene-maleic anhydride polymer esterified to about 100% half ester with monobutyl ether of ethylene glycol (Butyl Cellosolve) is charged to a reaction kettle containing an amount of water to give 35% solids concentration. The partial ester is added slowly with agitation to avoid formation of clumps of the partial ester. The temperature of the water-partial ester slurry is raised to 6070 C. and maintained at this temperature. After the 60-70 C. temperature is obtained, 60 parts of ammonium hydroxide solution at 26 B6. is slowly added to the waterpartial ester and reacted until the partial ester is in solution as the ammonium salt of the partial ester. The pH of the resulting hydrolyzed 35 solution of the ammonium salt of the partial ester of styrene-maleic anhydride polymer with monobutyl ether of ethylene glycol is about 9.0-9.5.

For purposes of tests two polyvinyl acetate latex white paint base formulations A and B are prepared as shown in Table I and employed ill the examples. However, any polyvinyl acetae lalex whltg g. base. composmon The additional dispersant added to sample 4 was a gontammg a l plgment lspersmg agent can physical blend of the octylphenyl polyethoxy alcohol e emPkYed e Present mventmn- (Triton X-lOO) in the ratio of 3.7 lbs. and the hydrolyzed ammonium salt solution (37% non-volatile resin) of the TABLE I POLYVINYL ACETATE LA EX WEI E I 1:1 styrenel-mzlrleic anhydride pollymer in the ratio of 1.4

- T T PA NT lbs. non-vo ati e resin per 1090 l s. of aint.

BASE FORMULATIONS The additional dispersant added to simple 5 was the Five samples were prepared of the polyvinyl acetate latex white paint base formulation A, each of which con- 5 tained the hydrolyzed ammonium salt of the ethylene glycol monobutyl ether ester of styrene-maleic anhydride polymer, prepared as in Example C, and used as the pigment dispersant during the physical dispersion process in the Waring Blendor.

Sample 1 contained the ammonium salt of ethylene glycol monobutyl ether ester of styrene-maleic anhydride polymer, used as the pigment dispersant during the physical dispersion process in the Waring Blendor, and no additional dispersant was added thereto.

Additional dispersants were added to each of samples 2, 3, 4 and 5 and incorporated by stirring. The additional dispersant added to sample 2 was the octylphenyl polyethoxy alcohol containing 9 to 10 ethoxy groups (Triton X-100), not the ester, in the ratio of 3.7 lbs. per 1090 lbs. of paint.

The additional dispersant added to sample 3 was the hydrolyzed ammonium salt solution (37% non-volatile resin) of the 1:1 styrene-maleic anhydride polymer, not the ester, in the ratio of 1.4 lbs., non-volatile resin per 25 1090 lbs. of paint.

hydrolyzed solution (14.5% non-volatile resin) of the Water 2 261 ammonium salt of the octylphenyl polyethoxy alcohol HydmlYZed ammmmln salt monobutyl ether of (Trlton X100) ester of the 1:1 styrene-maleic anhydride ethylene glycol partial ester of styrene-malele an- 1 f E 1 B f h hycindepol rner tExampleo 35%so1 tlon) 12,4 p0 ymer o xamp e 0 t 18 invention in t e ratio of 2 3?g Polymem dlspefsmg agent 4 3 5 lbs. non-volatlle resln per 1090 lbs. of paint. Commercial nofiohl'hlli il 'agt'ht' (addition There was added to each of samples 1 to 5, after inghz o Oxide to polypropylene gly- 3 8 cor oratlon of addltlonal dlspersants to samples 2 to 5, Commercial titanium al'oh'dhlhlatliijjjiiijliiiii "no 1'50 40 a set forth above, 8 Of a commercial lampblack paint g figigg Whlte Plgment 0f magneslum 150 150 um colorant per gallon of polyvinyl acetate latex white Silica Nailed III. l o paint base formulation A.

Drawdowns and flocculation rub-ups were made with each of the five lampblack colored samples with the re- 45 sults shown in the following table.

TABLE II Colorant Sample Dispersant flocculation 1 Hydrolyzed armnonium salt of ethylene glycol monobutyl ether ester of styrenemaleic anhydride polymer Very extreme Additional dispersant 2 Octylphenyl polyetlloxy alcohol (Triton X-100) Very extreme.

3 Hydrolyzed ammonium salt of styrene-maleic anhydride polymer D 4 Physical blend of octylphenyl polyethoxy alcohol (Triton X-100) and the hydrolyzed ammonium salt of styrene-malele anhyhydride polymer Extreme.

5 Ammonium salt of octylpllenyl polyethoxy alcohol (Triton X-100) ester of styrene-maleic anhydride polymer of this lnvention None.

The above portions of the formulations are dispersed Optimum color development with no flocculation was by stirring in a Waring Blendor and then there is added: achieved in sample 5 by using the ammonium salt of the octylphenyl polyethoxy alcohol ester of styrene-maleic anhydride polymer in the polyvinyl acetate latex white Commercial polyvinyl acetate emulsion 285 285 Commercial mthylcenulose thickening agent 4% palnt base folmulatlon A whlch contalned the hydrolyzed Dagiget'iussollutloln 13 13 ammonium salt of ethylene glycol monobutyl ether ester 1e y enegyco 1 1 Monoethylether ofdiethylene glycol (Carbitol) 25 25 of Styrene anhydr.lde P as a plgrtlent. dls

Commercialphenylmereuricacetate 2.5 2.5 P 'S nlI. Thus thlS combination Of dlspersants 1S hlghly effective. However, sample 1 of formulation A contain- Total 1,089.9 1,085.6

. mg only the hydrolyzed ammonlum salt of ethylene glymulailon A Was P ePaTed by 115mg the hydrolyzed col monobutyl ether ester of styrene-maleic anhydride 35% solution of the ammonium salt of ethylene glycol polymer gave very extreme flo l ti monobutyl ether ester of styrene-maleic anhydride polymer of Example C as the pigment dispersant during the Example II physical dispersion process in the Waring Blendor.

Formulation B was prepared by using a commercial FlVe Samples were P p of the P y y acetate dispersant system of an anionic polymeric dispersing latex white paint base formulation B, each of which conagent (Tamol 731) and a nonionic surface-active agent, tained a commercial anionic polymeric dispersing agent addition product of ethylene oxide to polypropylene gly- (Tamol 731) and a commercial nonionic surface-active cols (Pluronic L-62), as the pigment dispersant during agent, addition product of ethylene oxide to polypropylene the physical dispersion process in the Waring Blendor. glycols (Pluronic L-62) used as the pigment dispersant system during the physical dispersion process in the Warhydride polymer and octylphenyl polyethoxy alcohol ing Blendor. causes colorant flocculation and thus are not effective Sample 1 contained the commercial anionic polymeric as colorant dispersants. These tests show that the amdispersing agent (Tamol 731) and the commercial nonmonium salt of the octylphenyl polyethoxy alcohol ester ionic surface-active agent, addition product of ethylene of styrene-maleic anhydride polymer of this invention is oxide to polypropylene glycols (Pluronic L-62), used as the elfective colorant dispersant. the pigment dispersant during the physical dispersion Other paint tint colorants, monastral red and medium process in the Waring Blendor and no additional disyellow, were dispersed in polyvinyl acetate latex white persant was added thereto. paint base formulations with the ammonium salt of the Additional dispersants were added to each of samples octylphenyl polyethoxy alcohol ester of styrene-maleic 2, 3, 4, and 5 and incorporated by stirring. The addianhydride polymer of this invention and gave similar tional dispersant added to sample 2 was the hydrolyzed results. ammonium salt solution (37% non-volatile resin) of the It is claimed: 1:1 styrene-maleic anhydride polymer, not the ester, in 1. A polyvinyl acetate latex white paint base composithe ratio of 1.4 lb. non-volatile resin per 1085 lbs. of tion containing a paint tint colorant dispersant composipaint. tion which comprises a mixture of an ammonium salt of t The additional dispersant added to sample 3 was the a partial ester of a styrene-maleic anhydride polymer octylphenyl polyethoxy alcohol containing 9 to 10 ethoxy esterified to about 75 to 1 00%; half ester with an alkylgroups (Triton X100), not the ester, in the ratio of 3.7 phenyl ether alcohol of the formula lbs. per 1085 lbs. of paint. I

The additional dispersant added to sample 4 was a R C6H4 (0CH2CH2)X OH physical blend of the octylphenyl polyethoxy alcohol Where R 15 alkyl f 3 t0 carbon atOmS d x S 1 t0 (Triton X-100) in the ratio of 3.7 lbs. and the hydrolyzed and all ammonlum Salt of a P ester of y ammonium salt solution (37 non-volatile resin) f maleic anhydride polymer esterified to about 75 to 100% the 1:1 styrene-maleic anhydride polymer in the ratio half ester with an alkyl ether glycol Selficted from the of 1.4 lbs. non-volatile resin per 1085 lbs. of paint. group consisting of alkyl others of ethylene glycol and of The additional dispersant added to sample 5 was the diothylono glycol wherein alkyl is about 1 to 8 carbons. hydrolyzed solution (14.5% non-volatile resin) of the each of Said styl'fille'maldc anhydride P y Prior ammonium alt of th octylphenyl polyethoxy l h l to esterification containing a molar ratio of polymerized (Triton X-100) ester of the 1:1 styrene-maleic anhydride Styrene t0 polymerized maleic anhydride of about 1 polymer of Example B of this invention in the ratio of t 4: and hav an average molecular Weight of about 5 lbs. non-volatile resin per 1085 lbs. of paint. 600 to 5000, and the ratio of said half ester with an alkyl- There was added to each of samples 1 t 5, fter the phenyl ether alcohol to said half ester with an alkyl incorporation of additional dispersants to samples 2 to ether g y being about 0511 to and wherein each 5 as set forth above, 8 oz. of a commercial sienna paint of said half esters is present in an amount of about 0.5

tint colorant per gallon of polyvinyl acetate latex white to 5.0 percent by weight with respect to the white pigpaint base formulation B. merit in said polyvinyl acetate latex white paint com- Drawdowns and flocculation rub-ups were made with position.

each of the five sienna colored samples with the results 2. A paint tint colorant dispersant composition of shown in the following table. 40 claim 1 wherein R in the formula of said alkylphenyl TABLE III C olorant Sample Dlspersant flocculation 1 Commercial anionic polymeric dispersing agent (Tamol 731) and commercial nonionic surface-active agent (Pluronic L-62)- Very extreme Additional dispersant Hydrolyzed ammonium salt of styrene-maleic anhydride polymer Very extreme 3 Octylphcnyl polyethoxy alcohol (TritonX-IOO) Do. 4 Playstiical bllend of octyphenyl polyethoxyl alcohol Triton 00) and the hydro zed ammonium salt of styren maleic anhy- D l epo ymer o. 5 Ammr onium salt of octylphenyl polyethoxy alcohol (Triton X-lOO) ester of styrene-malelc anhydride polymer of this inven- N 1011 one.

Optimum color development with no flocculation was ether alcohol is tertiary-octyl, x is 9 to 10, said alkyl achieved in sample 5 by using the ammonium salt of the ether glycol is monobutyl ether of ethylene glycol, and

octylphenyl polyethoxy alcohol ester of styrene-maleic each of said styrene-maleic anhydride polymers prior to anhydride polymer in the polyvinyl acetate latex white esterification contains a molar ratio of polymerized stypaint base formulation B which contained the commerrene to polymerized maleic anhydride of about 1:1 and cial anionic polymeric dispersing agent and the commerhas an average molecular weight of about 1500 to 2000. cial non-ionic surface-active agent as a pigment dis- 3. In a polyvinyl acetate latex white paint base compersant. Thus the colorant dispersant of this invention, the position containing a white pigment and a dispersing ammonium salt of the octylphenyl polyethoxy alcohol agent for said white pigment, the improvement which ester of styrene-maleic anhydride polymer, is generally 65 comprises said dispersing agent for said white pigment effective in commercial polyvinyl acetate latex white comprising from about 0.5 to 5% by weight of said white paint base compositions containing a white pigment and pigment of an ammonium salt of a partial ester of a conventional dispersing agents for the pigment. However, styrene-maleic anhydride polymer esterified to about 75 sample 1 of formulation B containing only the commerto 100% half-ester with monobutyl ether of ethylene cial dispersing agent for the pigment gave very extreme glycol and an additional dispersing agent therein of about flocculation. 0.5 to 5% by weight of said White pigment to effectively In the examples, it is shown that the octylphenyl polydisperse a paint tint colorant in said white paint base ethoxy alcohol, the hydrolyzed ammonium salt of the composition without flocculation, said additional disstyrene-maleic anhydride polymer, and a mere physical persing agent being an ammonium salt of a partial ester blend of the ammonium salt of the styrene-maleic anof a styrene-maleic anhydride polymer esterified to about 75 to 100% half-ester with tertiary octylphenyl poly ethoxy alcohol of the formula where x is 9-10, and each of said styrene-maleic anhydride polymers prior to esterification contains a molar ratio of polymerized styrene to polymerized maleic anhydride of about 1:1 and has an average molecular weight of about 1500 to 2000.

4. In the polyvinyl acetate 'latex white paint base composition of claim 3, wherein said white pigment comprises titanium dioxide pigment, a paint tint colorant dis persed therein in amount of about 1 to 16 oz. per gallon of said composition.

References Cited UNITED STATES PATENTS DONALD J. ARNOLD, Primary Examiner J. B. LOWE, Assistant Examiner US. Cl. X.R. 

